Absolutely. Not to mention that is a Pokemon Diamond/Pearl stage and Lucario is a Diamond/Pearl character. It appears Sakurai just had to make due with the act of revealing Lucario first. And since you were willing to copy me, allow me to copy you.
Prediction for Feb. 29, 2008:
(General) Stage update
(Specific) Pokemon Diamond/Pearl - Spear Pillar
(SuperSpecific) It can be unlocked by clearing Event Mode #25
And just in case Sakuria decides to cash in on Pokemon, double update prediction:
2nd Prediction for Feb. 29, 2008:
(General) Character Profile
(Specific) Jigglypuff
(SuperSpecific) Jigglypuff can be unlocked in Brawl by completing Classic Mode with any character except Ike.